Adipose tissue as a medium for epidemiologic exposure assessment.

In the United States, adipose tissue is rarely used as a medium for assessment of prior exposures in epidemiologic studies. Adipose tissue aspirations are in general less invasive and carry less risk than phlebotomy. Tissue samples can be analyzed for a wide number of epidemiologically important exposures. Beyond reflecting long-term energy balance, this tissue offers a relatively stable depot of triglyceride and fat-soluble substances, such as fat-soluble vitamins, and pesticides. As a tissue it represents the greatest reservoir of carotenoids in the body. Halogenated hydrocarbons may be measured in concentrations of hundreds-fold greater than those in blood of the same individuals. The composition of adipose tissue also reflects the long-term dietary intakes of a number of essential fatty acids. The turnover times of all of these substances in adipose tissue remain under-researched. Sampling and storage of adipose tissue, homogeneity of sampling sites, turnover times, and the effects of diet, age, gender, race, hormones, and disease on adipose tissue composition are discussed in this review of current knowledge about adipose tissue stability. Experience in the use of adipose tissue sampling in epidemiologic studies in various countries has shown that it is simple to conduct, requires little training, carries little risk, and does not result in excessive participant refusal

Ethical Reasoning and Risk-Taking When Teaching Patriotism and War. A Response to “The Foot and the Flag: Patriotism, Place, and the Teaching of War in a Military Town”

Gibbs’s detailed description of decision-making around teaching war in a school that taught the children of active-duty soldiers provides an important glimpse into the numerous factors influencing their curricular and pedagogical choices. Gibbs rightly argued that the limited perspective of patriotism that resulted from the teachers’ reluctance to engage their students in a critical analysis of the justness of U.S. wars and foreign policy gives us concern for a robust, liberal democracy. The fear the teachers articulated in broaching the controversial aspects of war correspond to teachers’ reluctance to tackle numerous other controversial topics such as race/racism, religion, politics, class, gender identity, and sexual orientation. Balancing the need teachers share to engage their students in the exploration of complex social issues with a desire to shield students from harmful or uncomfortable interactions involves complex decision-making and ethical judgments. It always involves taking risks by both teachers and students. I propose the jurisprudential framework as a practical guide in developing units around social issues and professional development based in developing collaborative communities of practice in order to create the support necessary for teachers and students to take these risks

Instructional Support for Vocabulary Acquisition Among Young Dual Language Learners

This dissertation examined a combined approach to teach novel vocabulary in English and Spanish for dual language learners prior to an English storybook read- aloud in a preschool setting. The 6-week intervention study was conducted in a Head Start program in the U. S. Mountain West with 60 dual-language preschoolers randomly assigned to small groups to receive the vocabulary intervention, using images and word definitions from researcher-trained teachers, teacher assistants or parent volunteers. The experimental design included pre- and posttest assessments of target and general receptive vocabulary in English and Spanish, as well as language exposure, instructional quality, and fidelity of treatment. Teachers demonstrated a high level of fidelity in the preteaching of vocabulary in small groups. A multiple regression analyses and t-test comparisons indicate that preschoolers made comparable gains in breadth and depth of target vocabulary in Spanish and English, with higher definitional gains of vocabulary outcomes among those receiving vocabulary instruction in Spanish. For example, the Spanish-language group provided more diverse and robust definitions for target words. The results suggest that an explicit, target vocabulary intervention can improve Spanish-speaking preschoolers’ academic vocabulary in Spanish and English. Use of the home language seemingly supported word learning in both Spanish and English and appeared to increase linguistic awareness more than those receiving only English. The brief, small-group, vocabulary instruction was relatively easy to implement and shows promise as a curricular component available to Head Start programs. Implications for instruction and future research are included

Director configuration in the twist-bend nematic phase of CB11CB

The director distribution in the nematic phases exhibited by the 100,1100-bis(4-cyanobiphenyl-40-yl)undecane (CB11CB) liquid crystal has been studied in the bulk with the EPR spin probe technique. EPR spectra confirmed the presence of an higher temperature uniaxial nematic phase and of a lower temperature nematic phase in which the director distribution is not uniform. Spectra recorded in the lower temperature nematic phase were not fully compatible with theoretical EPR spectra calculated according to the recently proposed model for the twist-bend phase in which the local domain director twists around an axis with a fixed tilt angle, θ₀, but were well described by a “distributed-tilt” model in which the director has a relatively narrow distribution, centred at θ₀

On the structure of the Nx phase of symmetric dimers: inferences from NMR

NMR measurements on a selectively deuterated liquid crystal dimer CB-C9-CB, exhibiting two nematic phases, show that the molecules in the lower temperature nematic phase, NX, experience a chiral environment and are ordered about a uniformly oriented director throughout the macroscopic sample. The results are contrasted with previous interpretations that suggested a twist-bend spatial variation of the director. A structural picture is proposed wherein the molecules are packed into highly correlated chiral assemblies

NMR study of a bimesogenic liquid crystal with two nematic phases

Recent interest in bimesogenic liquid crystals showing two nematic phases has led us to investigate the nematic mean-field interactions in these nematic phases by using rigid solutes as probes. The nematic potential that is modelled by two independent Maier-Saupe terms is successful in fitting the observed dipolar couplings (order parameters) of para-, meta- and ortho-dichlorobenzene solutes in both the nematic phases of 39 wt% of 4-n-pentyl-4′-cyanobiphenyl (5CB) in α,ω-bis(4-4′-cyanobiphenyl)nonane (CB_C9_CB) to better than the 5% level. The derived liquid-crystal potential parameters G₁ and G₂ for each solute in the N and Ntb phases will be discussed. The most interesting observation is that G1 (associated with size and shape interactions) is almost constant in the Ntb phase, whereas G₂ (associated with longer-range electrostatic interactions) has large variation, even changing sign

A Call to Arms: Interferons Prepare Bone Marrow Cells to Battle Peripheral Infections

Viral infection leads to the rapid production of type I interferons within infected tissues. In this issue of Cell Host & Microbe, Hermesh et al. (2010) demonstrate that interferons produced following respiratory viral infection program leukocytes in the bone marrow to resist infection before trafficking to the lung